A Centralized Priority Based RWA Protocol for WDM Networks

In this protocol we use appropriate RWA methodologies depending on the priority and speed of the incoming traffics to identify the optimal lightpaths. As request arrives, centralized management system (CMS) identifies the traffic class depending on their priority and speed. Accordingly CMS uses appropriate RWA methodologies to identify the optimal lightpaths. To give more importance to high priority request the available wavelength set is divided into two subsets, called P set of higher order wavelengths and C set of remaining wavelengths. Protocol first tries to find an optimal lightpath for high priority request using wavelengths from subset C, else finds out using P. Lightpaths for low priority traffics are found by only using subset C. Further for survivability backup lightpath is maintained. The selection of backup lightpath is done in such a way that there is no shared link between the primary and backup lightpath. By simulation results, we have shown high priority requests have low blocking probability.